Northern San Juan

Snowpack

Bill Nalli Jeff Davis · Jan 5, 2020 · Northern San Juan

Weather

The wind dominates the story. Very strong SW winds at times gusting over 40mph. Blowing snow on all aspects in the alpine. Once near and below treeline conditions were much more calm.

Snowpack

Most of the loading was onto northeast and east slopes but north and southeast aspects also have a new hard slab at the surface. As often the case with very strong winds, loading was mostly far down off ridges but terrain channeling has every aspect affected in some way. Either stripped or loaded. The slab is very stubborn. We jumped (very hard) on a few test slopes and could not get any reaction. We also didn't get onto any big steep slope with larger consequences where most of the loading was taking place. One snow profile on a northeast aspect at 12,600 feet showed a very deep snowpack of 240cm. Extended column test results confirmed this stubborn condition but the slab did propagate after 23 taps. Most terrain at treeline and below was spared from this onslaught of wind and has a variety of soft recrystallized snow or thin fragile sun crust at the surface. Not all near treeline slopes were spared however. See photo of the north flank of Red 3.